Containerless study of metal evaporation by laser induced fluorescenceLaser induced fluorescence (LIF) detection of atomic vapors was used to study evaporation from electromagnetically levitated and CW CO2 laser-heated molybdenum spheres and resistively-heated tungsten filaments. Electromagnetic (EM) levitation in combination with laser heating of tungsten, zirconium, and aluminum specimens was also investigated. LIF intensity vs temperature data were obtained for molybdenum atoms and six electronic states of atomic tungsten, at temperatures up to the melting point of each metal. The detected fraction of the emitted radiation was reduced by self-absorption effects at the higher experimental temperatures. Vaporization enthalpies derived from data for which less than half the LIF intensity was self-absorbed were -636 + or - 24 kJ/g-mol for Mo and 831 + or - 32 kJ/g-mol for W. Space-based applications of EM levitation in combination with radiative heating are discussed.
Document ID
19880041360
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Schiffman, Robert A. (Midwest Research Inst. Kansas City, MO, United States)
Nordine, Paul C. (Midwest Research Institute Kansas City, MO, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Materials Processing
Meeting Information
Meeting: Materials processing in the reduced gravity environment of space